BACKGROUND : Hospital-acquired hepatitis B virus (HBV) infection has been well described and continues to occur worldwide. Recent nosocomial outbreaks have been linked to unsafe injection practices, use of multi-dose vials, and poor staff compliance with
standard precautions. This report describes a nosocomial outbreak that occurred in a
paediatric haematology and oncology unit of a large academic hospital, the epidemiological investigation of the outbreak, and preventive measures implemented
to limit further in-hospital transmission.
METHODS :Outbreak investigation including contact tracing and HBV screening were initiallycarried out on all patients seen by the unit during the same period as the first three
cases. Routine screening for the entire patient population of the unit was initiated in
February 2013 when it was realised that numerous patients may have been
RESULTS : Forty-nine cases of HBV infection were confirmed in 408 patients tested between July 2011 and October 2013. Phylogenetic analysis of the HBV preC/C gene
nucleotide sequences revealed that all tested outbreak strains clustered together.
Most (67%) patients were HBeAg positive. The cause of transmission could not be
established. Preventive measures targeted three proposed routes. HBV screening
and vaccination protocols were started in the unit.
CONCLUSIONS : The high number of HBeAg positive patients, together with suspected lapses in infection prevention and control measures, are believed to have played a major role in the transmission. Measures implemented to prevent further in-hospital
transmission were successful. On-going HBV screening and vaccination
programmes in paediatric haematology and oncology units should become standard